\[ y'(x)=x \sqrt {a^2 x^2+2 a b x+4 a y(x)+b^2-4 c}-\frac {a x}{2}-\frac {b}{2} \] ✓ Mathematica : cpu = 0.433611 (sec), leaf count = 51
\[\left \{\left \{y(x)\to \frac {a^2 \left (-\left (4 c_1+1\right ) x^2+4 c_1^2+x^4\right )-2 a b x-b^2+4 c}{4 a}\right \}\right \}\]
✓ Maple : cpu = 0.271 (sec), leaf count = 41
\[ \left \{ {\it \_C1}+a{x}^{2}+{\frac {a}{2}}-\sqrt {{a}^{2}{x}^{2}+2\,abx+{b}^{2}+4\,ay \left ( x \right ) -4\,c}=0 \right \} \]